Abrasive nozzles for use in combining fluid and abrasive material for producing a high pressure jet have been found to be highly effective for removing debris and applying anchor patterns on various types of surfaces. One such nozzle is taught in U.S. Pat. No. 5,054,249. Additionally, "shape jet nozzles" for producing small, high pressure, cohesive, non-circular jets of fluid are known, as taught in U.S. Pat. No. 5,170,946. However, due to the unfocused and wide spray patterns of known abrasive nozzles and the inability of using abrasive material with shape jet nozzles, no known nozzles have heretofore had any application for precision material cutting or precision material separation applications. Although not so limited, a focusing nozzle of the present invention is particularly suited for producing and jetting a precisely focused, sustained, cohesive jet of a mixture of fluid and abrasive material, having a prolonged centerline pressure, for use in producing clean, precise and sharp-edged kerfs in generally hard substances, such as for example, iron, steel, concrete, cinder blocks, brick, tile and glass. Additionally, the focusing nozzle of the present invention is designed for use with high or low pressure fluids and for use with various abrasives. The clean, precise and sharp-edged kerfs produced by the present invention are essential for precision cutting and precision material separation applications.
The ability to make clean, precise, sharp-edged kerfs, grooves or cuts in hard surfaces is of particular interest in the areas of metal working and construction. It is well known that a gear or cog may be cut from a flat sheet of steel via methods of flame cutting and/or mechanical saws, which processes use large quantities of energy and create high temperatures. Similarly, concrete, glass, tile, brick, and other forms of masonry products can be cut and separated using metallic or fibrous saw blades. The drawbacks to both of these processes, i.e. flame cutting and mechanical sawing, include the creation of large quantities of heat and friction. Additionally, both processes create the potential for adversely altering the qualities of the material being cut, especially at or near the cut edge. For instance, steel may be tempered through the process of flame cutting and sawing, increasing its brittleness and thereby losing some of its tensile qualities. Likewise, a masonry saw may adversely temper or alter the qualities of the material at or near the cut edges of the brick, concrete or tile.
This type of heat induced material alteration may not always be a desired result and may actually be quite destructive to the product which is ultimately manufactured from the material. In fact, not only is the material to be cut typically altered during exposure to heat, but a great deal of energy must be created and consumed to produce the heat necessary for flame cutting and sawing.
Heretofore, there have been no devices which produce clean, precise, sharp-edged kerfs, grooves and cuts in hard surfaces in the absence of using a flame, saw or heat producing cutting process, which may adversely affect inter alia the cut-edge. Therefore, a need exists for an apparatus to produce clean, precise, sharp-edged cuts, kerfs and grooves in hard substances such as iron, steel, concrete, tile, brick and glass for the purpose of precision cutting and precise material separation in the absence of experiencing the undesirable effects from heat. Additionally, the need exists for an apparatus to produce clean, precise, sharp-edged cuts, kerfs and grooves in hard substances such as iron, steel, concrete, tile, brick and glass using a mixture of fluid and abrasive material having a cool or moderate temperature.
Although the need for such a device has been long felt, the prior art, heretofore, has not provided such a device which meets all of the aforementioned criteria and avoids the above-referenced problems.
Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will become apparent, from the description or may be learned by practice of the invention. The features and advantages of the invention may be realized by means of the combinations and steps particularly pointed out in the appended claims.